What happens to Sophie's parents in the Wanderer by Sharon Creech?

So, when Sophie goes to see Bompie, she retells his own stories to him that she learned from letters he sent to her. Then she tells him one story he doesn't recognize and it ends up to be her own story :(

(this part is from Cody's perspective)

"Bompie, remember when you were very little, just a child, and you went sailing with your parents?"

"I did?" he said

"Out on the ocean, the wide blue, blue, ocean. And you were sailing, sailing along and then the sky got very gray and the wind started to howl-- remember?"

He looked at her, blinked a few times, but said nothing.

"The wind, remember? It was howling, howling, howling, and the boat was rolling, and it got so cold, and your mother wrapped you in a blanket and put you in the dinghy-- remember?"

Bompie stared at her, but still he said nothing.

Sophie rushed on, "Remember? Remember? And--and-- the wind--the cold-- and water, a big wall of black water coming down over you and then you were floating, floating, floating-- and-- and-- the parents-- the parents--"

She looked at me, pleading, and suddenly so much was clear to me. I knelt on the other side of the bed. "The parents didn't make it," I said.

Sophie gasped. "The parents didn't make it," she repeated, and then she rushed on: "And then you were all alone, Bompie, all by yourself, floating, floating--"

Bompie said, "But I--"

I reached across the bed and touched her hand. "Sophie," I said. "Maybe that's not Bompie's story. Maybe that's your story."

So sad TT^TT This was in Chapter 73 :)